Process of purifying para-nitraniline



the formation ofsuch precipitate and thus topurify the nitraniline by a suitable treatment Patented Mar. 8,1932 V NI E TA res ALFRED MILLERQ F BUFFALO, NEW vonmnssieivon TO rrownn C0.,I1\TC. ,A CORPORATION ornnwvonx MANUFACTURING rnoonss or IPIJ'RIFYING fP'AnA-Nrrimm INE I N'o Drawing. originalapplication leaaui 14,-;1925Qsri if1srO. 43,018,

filed June 5, 1928;

This'invention relates to a new process of purifying or treating nitraniline, specifically para-nitraniline. para-nitraniline from para-nitro-chlor-benzene With ammonia under pressure, certain by -products are formed, as -descrlbed by Ullman, Enzyklopadieder technischen Chemie, Vol. 1, page 440, and these have the efl'ectof causing a flocculent precipitate to form when thenitraniline is diazotized. V r

It is an objectof this invention to prevent with a reducing, agent or its equivalent. In

accom 'c-lishingthis result I treat the nitrani line with either a neutral, acid or alkallne re ducing agent in suitable proportions at an elevated temperature, as is more fully dlsclosed in the following example's and in my Patent No. 1,673,154, June 12, 1928, of which this application is a division.

One hundred and sixty parts of crude para-i nitraniline are suspended in2800 parts'of water. 6 to 8 partsof sodium sulphide crystals are dissolved in200 parts or" Waterv and filtered free from any sediment which may be present. The solution of sodium sul- V phide is added to the suspensionof para-nitraniline and the charge is heated up to to C. with constant agitation. Itis' then cooled to 40 to 45 C., filtered, and washed with water. The resulting para-nitraniline gives a clear diazo solution. I

As a secondexample, I suspend parts of crude para-nitraniline in 2500 parts of water, and then add a solution of ammonium sulphide containing 2 to 2% parts'of 100% ammoniumsulphide. ,The liquid is heated to 90to 100 0., thereafter cooled to 30 to 35 0., filtered, and washed well. 7

' In-these examples 'I have named mild reducing agents which reduce the nitro bodies,

or other impurities present but which do not afiect'the nitraniline molecule itself, that is to say, there is no reduction of the N0 attached to the benzene nucleus. tity of reducing agentvemployed whatsoever source derived and it In the manufacture of r V u may be made"ivithout departing from the principle thereof it is to be 'understoodthatl' 'mentsi except 'impurities'rnore easily -roup The quam is propori tioned to the amount of 'impurity present,

may also be applied at any suitable point the manufac tureof nitraniline." y Y I 7 As v'arlous embodimentsof the 1nvent1on do not limit myself to; the foregoing embodif asdefined in the "following ;-I claim-:i v V m Q1. The process consisting. in'jjtreating" a nitraniline "derived iiitro-chlor 'benzme jwith ammonia and con;' taining impurities 'morc easily reduced than nitraniline with an -alkaline'sulphideto're- 1 the mp s W Q i re ucing he nitraniline.

do w from tl etre'atinent The process-consisting intreating ars; 'nltranilinefderived. from the treatment of nitrofclilor-benzine with ammonia an'dicon' mini;is imp it es m e i y iedu that paranltran llne,

. ith a alkaline sulphide I, V Y i to reduce the impurities without reducing 5 the para-nitraniline.

. g Th process'consistingiii'treating n1;

traniline derived from the treatment Genius; chlor-benz'ine [with ammonia and. containing line, with an alkaline sulphide,- heating the charge nearly to the boiling point, cooling, filtering and washing, "with water, whereby there is'obtained" apurified nitraniline. v 4. The process consisting in treating'parae nitraniline" derived from the treatment of" nitro ch'lor-benzine with ammonia an'd'containing impurities more easily reduced than the par'a-nitranilineY with an alkaline sul-v phide, heatingthe' charge nearly'to the boil ing point, cooling, filtering and washingwith water, whereby thereis obtained a purifiedpara-nitraniline. V V 5. The process consisting in treating 31111-1 traniline derived from the treatment of nitro reduced than nitrani-Q i chlor-benzin-e with'ainmonia, in aqueous suspension with an alkaline heated nearly to the boiling'point,

6. The process consisting in treating para- 2 I nitranilinev derived from the treatment of nitro-chlor-benzlnewith ammonia, in aqueous nearly to the boiling point.

suspension with an alkaline solution heated sulphide solution c .I

7. In the manufacture of nitraniline from nitro-chlor-benzene with ammonia wherein certain icy-products are formed which cause a fiocculent precipitate upon diazotation, the

5 process characterized in reducing said by products by means of an alkaline sulphide in dilute solution.

8. In the manufacture of nitraniline from nitro-chlor-benzene with ammonia wherein certain by-products are formed which cause a flocculent precipitate upon diazotation, the process characterized by reducing said byproducts with an alkaline sulphide in dilute aqueous solution, heating to 'a temperature below boiling and thereafter filtering 05 the solution from the nitranilin-e.

9. The process consisting in treating a nitraniline derived from the treatment of nitrochlor-benzine with ammonia and containing impurities more easily reduced than the nitraniline, with sodium sulfide to reduce the impurities without reducing the nitraniline.

10. The process consisting in treating paranitraniline derived from the treatment of nitro-chlor-benzine with ammonia and containing impurities more easily reduced than para-'nitraniline, with sodium sulfideto reduce the impurities without reducing the para-nitraniline.

so 11. The process consisting in treating para: nitraniline derived from the treatment of nitro-chlor-benzine with ammonia and containing impurities more easily. reduced than V the 'para-nitraniline, with sodium sulfide,

as heating the charge nearlyto the boiling point,

cooling, filtering and washing with water,

whereby there is obtained a purified paranitraniline. V r

.12. The process consisting. in treating a V '40 nitraniline derived fronr the treatment of nitrO-chlon-benzine with ammonia in aqueous suspension with. sodium sulfide: solution heated nearly to the boiling point.

13. In the manufacture of nitraniline from 4; nitro-chlor-benzine with ammonia wherein certain by-products are formed which cause a flocculent precipitate upon diazotation, the process characterized in reducing said byproducts by means of sodium sulfide in dilute solution. 1 v V In testimony that I claim the foregoing, I have hereunto set my hand this 29 day of May, 1928. a t V ALFRED MILLER. 

